Pressure equalizing valve

ABSTRACT

Refrigerated equipment is provided with an air passage through a wall thereof. A closure member within the passage is movable in opposite directions in response to overpressure or under pressure created within the refrigerated space upon opening or closing of a door. The closure member substantially completely closes the passage and means are provided for preventing the formation of ice between the sides of the passage and the closure which might otherwise interfere with the movement of the closure.

United States Patent Burtis [4 1 Aug. 1, 1972 [54] PRESSURE EQUALIZING VALVE 3,l23,867 3/1964 Combs ..49/21 72 Inventor: Wi l R. Burt's, Trenton 3,167,931 2/1965 Bryson ..62/273 [73] Assignee: Emhart Corporation, Bloomfield. FOREIGN PATENTS 0 PP CAT ONS 1,370,843 7/1964 France ..981119 [22] Filed: Feb. 18, 1971 P E w J w nmary xammer- 1 ram ye [211 App! "6510 Att0rney'Sperry & Zoda [52] US. Cl. ..62/275, 62/273, 98/ l 19, [57] ABSTRACT.

51 I t 49/21 fggg: Refrigerated equipment is provided with an air d passage through a wall thereof. A closure member 1 o 6 37/215 within the passage is movable in opposite directions in response to overpressure or under pressure created within the refrigerated space upon opening or closing [56] admin Cited of a door. The closure member substantially complete- UNITED STATES PATENTS ly closes the passage and means are provided for preventing the formation of ice between the sides of 2,139,991 12/1938 Wmgard ..98/119 the passage and the closure which might otherwise g; w l

terfere with the movement of the closure.

0 ve on v 2,798,422 7/1957 Bourque ..98/1 19 6 Claims, 3 Drawing Figures PATENTEDMIB I 1912 I N VEN TOR. wmneap e. BzRTIS BY M ATTORNEYS PRESSURE EQUALIZING VALVE FIELD OF THE INVENTION Refrigerated equipment provided with doors for permitting access to the refrigerated space therein are generally made as air tight as possible to prevent undesired flow of air into and out of the refrigerated space. This is necessary not only for the purpose of reducing refrigeration losses, but also in order to reduce the accumulation of ice and frost on the evaporator coils and the walls and other refrigerated surfaces within the refrigerator. However, because of the air tight condition thus established, it is frequently difficult to open and close the doors to the refrigerated space due to the inability of air to enter or leave the space upon movement of the door. Moreover, as the temperature of the air within an enclosure is'reduced, the volume and pressure of the refrigerated air are reduced, rendering it very difficult to open a door to the refrigerated space, particularly, when such space is relatively large as in the case of large storage equipment.

While it has been suggested heretofore that one way valves might be located in a passage through the wall of refrigerated equipment, such valves have not permitted the passage of air in opposite directions therethrough, as for example when a door is opened and closed. Moreover, the condensation and freezing of moisture on or about relief valves in refrigerated equipment prevents or interferes with the proper operation of such valves and sometimes renders them completely inoperative.

THE PRESENT INVENTION In accordance with the present invention, refrigerated equipment is provided with a passage through a wall thereof through which air may flow to equalize the pressure on the interior and exterior of the refrigerated space upon opening or closing of a door to the space or upon change in pressure of the air within the space. A valve member substantially closing said passage is movable in opposite directions in response to differences in pressure on opposite sides thereof and heating means are provided for preventing condensate about the edges of the valve member from freezing or otherwise interfering with the operation of the valve member.

THE DRAWINGS FIG. 1 is a diagrammatic view of a portion of a refrigerated fixture embodying the present invention;

FIG. 2 is a vertical sectional view of a typical. valve and passage assembly embodying the present invention; and

FIG. 3 is a sectional view of the construction shown in FIG. 2, taken along line 2-2 thereof.

In that formof the invention chosen for the purposes of illustration in the drawing, a refrigerated fixture is represented as 2 and is provided with a door 4 movable to open and closed positions to provide access to the interior of the fixture. The fixture has insulated walls and preferably is substantially airtight in its construction to prevent loss of refrigeration and to reduce the accumulation of frost and ice upon the evaporator and other surfaces within the fixture.

A pressure relief valve assembly is located at a suitable point in the fixture as, for example, in a wall portion 6 above the door 4. The assembly preferably comprises a duct member 8 located within a passage 10 extending from the interior 12 to the exterior 14 of the fixture. The duct member may be in the form of a metal shell which is rectangular in cross section and provided with a flange 16 which projects outward so as to overlie the metal shell or inner surface layer 18 of the wall fixture. The flange 16 is preferably insulated from the surface 18 by a gasket 20 and is secured to said surface by screws or other fastening means 22. The outer end 24 of the duct member 8 is preferably held in place by a collar or bracket 26, secured to the outer metal shell or surface layer 28 of the fixture by fastening means 30. The collar is preferably provided with sealing means 32 for preventing the leakage of air into or out of the insulation 34 located between the inner surface layer 18 and the outer surface layer 28 of the wall 6 of the fixture.

A valve member 36 is located within the duct member 8 near the outer end thereof and is of such size as to substantially close the duct member and passage 35 therein to prevent unrestricted flow of air through the passage. However, the marginal edges of the valve member 36 are preferably spaced a small distance from the adjacent surfaces of the duct means 8. The valve member is pivotally mounted near the upper portion thereof for movement in opposite directions in response to differences in the pressure of the air on opposite sides of the valve member. Thus, the valve member may be provided with hinge pins 38 carried by plates 40 secured to the valve member 36 near the upper edge thereof and the hinge pins 38 may project in opposite directions through openings formed in inwardly turned tabs or flanges 42 carried by a frame member 44 surrounding the outer end 24 of the duct member 8. The valve member 36 is, therefore, readily movable to either of the dotted line positions indicated in FIG. 2, to permit the passage of air through the duct member in response to differences in pressure of the air on the interior and exterior of the fixture.

In order to assure free and ready movement of the valve member in response to differences in the pressure of air on the interior and exterior of the fixture, and avoid any danger of freezing of moisture or condensate between the edges of the valve member on adjacent surfaces of the duct member heating means are employed in the valve assembly. As shown in the drawing, such heating means may be in the form of electrical resistance elements 46 located in a space 48 between the outer surface of the duct means 8 and the insulation 34 about the passage 10 through the wall of the fixture 2. The heating elements 46 need only require sufficient power to raise the temperature of the surface of duct means 8 sufficiently to prevent freezing of any moisture or condensate which may be present between the valve member and the adjacent surface of the duct means.

In order to conceal the valve member and duct means and present a neat, attractive, appearance to the assembly, a decorative housing member 52, having an opening 50 therein, is preferably secured to the outer surface layer 28 of the fixture.

The construction thus provided renders it possible to open and close the door 4 more readily without need to overcome the differences in air pressure exerted on the inner and outer surfaces of the door by reason of the differences in temperature on the interior and exterior of the fixture or for any other reason.

1 claim:

l. A refrigerated cabinet comprising an enclosure having a door, operatively mounted therein;

said cabinet having at least one generally upright wall;

a passageway defined entirely through said upright wall to communicate an interior space, defined by said cabinet, with ambient;

a valve member hingedly mounted within said passageway;

said valve member normally serving to substantially block said passageway and being operable to swing open, in either direction, in response to a pressure differential being established across said valve member; and

a cover member mounted to extend over said passageway in spaced, generally parallel relationship with respect to said upright wall.

2. A refrigerated cabinet according to claim No. 1,

wherein:

said passageway is defined by a conduit, comprising a heat conductive material;

said conduit cooperates with internal portions. of said generally upright wall to define an inner space disposed contiguous to said conduit; and

heating means is operatively disposed within said inner space.

3. A refrigerated cabinet according to claim No. 1,

wherein:

- marginal edges of said flanges being spaced from said upright wall. 4.: A refrigerated cabinet according to claim No. 1,

wherein:

said passageway is formed to extend generally horizontally through said generally upright wall. 5. An apparatus according to claim No. 2, wherein said heating means comprises at least one electrical resistance heating element.

6. A refrigerated cabinet according to Claim No. 4,

wherein said valve is mounted to hinge about a generally horizontal axis extending generally transversely across an upper portion of said passageway. 

1. A refrigerated cabinet comprising an enclosure having a door, operatively mounted therein; said cabinet having at least one generally upright wall; a passageway defined entirely through said upright wall to communicate an interior space, defined by said cabinet, with ambient; a valve member hingedly mounted within said passageway; said valve member normally serving to substantially block said passageway and being operable to swing open, in either direction, in response to a pressure differential being established across said valve member; and a cover member mounted to extend over said passageway in spaced, generally parallel relationship with respect to said upright wall.
 2. A refrigerated cabinet according to claim No. 1, wherein: said passageway is defined by a conduit, comprising a heat conductive material; said conduit cooperates with internal portions of said generally upright wall to define an inner space disposed contiguous to said conduit; and heating means is operatively disposed within said inner space.
 3. A refrigerated cabinet according to claim No. 1, wherein: said passageway is defined by a conduit having a portion, protruding generally, normally, outwardly from an outer surface of said generally upright wall; marginal edges of said cover member being formed with flanges extending generally normally from said cover element and toward said upright wall, adjacent said protruding portion of said conduit; and marginal edges of said flanges being spaced from said upright wall.
 4. A refrigerated cabinet according to claim No. 1, wherein: said passageway is formed to extend generally horizontally through said generally upright wall.
 5. An apparatus according to claim No. 2, wherein said heating means comprises at least one electrical resistance heating element.
 6. A refrigerated cabinet according to Claim No. 4, wherein said valve is mounted to hinge about a generally horizontal axis extending generally transversely across an upper portion of said passageway. 